Android Firebase查询 [英] Android Firebase Query

问题描述

我有这样的结构

现在，我正在做这样的查询：

  DatabaseReference myRef = database.getReference（users）; 
 myRef.equalTo（6991580，ci）。addListenerForSingleValueEvent（new ... 
  

<然后我得到：
$ b

DataSnapshot {key = users，value = null}

所以，这个查询有什么问题？或者我做错了什么？

请注意，您需要告知Firebase您要订购/过滤的子物件：

  myRef.orderByChild（ci）。equalTo（6991580）。addListenerForSingleValueEvent（... 
  

另一种排序格式是一个常被误解的版本，我建议您避免使用它。 b $ b

I have this structure Now, Im making a query like this:

 DatabaseReference myRef = database.getReference("users");
        myRef.equalTo("6991580","ci").addListenerForSingleValueEvent(new ...

I was expecting the second node as result.. Then I get:

DataSnapshot { key = users, value = null }

So, what is wrong with this query? or maybe Im doing something wrong?

Best regards and thanks for reply.

解决方案

You need to tell Firebase what child property you want to order/filter on:

myRef.orderByChild("ci").equalTo("6991580").addListenerForSingleValueEvent(...

The other format of ordering is a commonly misunderstood version. I'd recommend simply staying away from it.

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